This application claims priority under 35 U.S.C. xc2xa7119 of German Application Serial No. 197 34 135.7 filed Aug. 7, 1997.
The present invention concerns a system which enables the user to process biological samples by contacting the sample with a matrix which binds the desired biological materials and subsequently eluting the biological materials from the matrix. This method of isolating biological materials is used especially in the field of cell analysis or nucleic acid analyses where relatively small amounts of biological materials are required.
Devices are already known in the prior art which use matrices to bind and purify nucleic acids. For example a vessel is described in EP-A-0 738 733 into which a liquid sample can be added which has a porous matrix on its underside to which nucleic acids can be bound by drawing the sample through the matrix. In addition a device is described in DE-4143394 which has a plurality of vessels arranged next to one another which have a layer of selectively adsorbing material at the bottom and an outlet opening on the underside of the vessels. The described arrangement of vessels is placed on a unit of sample holding vessels such that liquid from the former vessels pass into the collecting vessels after passage through the layer of adsorbing material. Furthermore the so-called QUIamp kit is known from the Quiagen Company whose function is shown in FIG. 1. Firstly a sample liquid together with a lysis buffer is added to a sealable vessel and a lysis of the mixture is carried out. In the subsequent step the lysis mixture is added to a vessel containing a matrix capable of specific binding and is drawn through the matrix by centrifugation and the emerging liquid is collected in a vessel. The matrix is subsequently washed and finally the adsorbed biological material is eluted.
A disadvantage of the prior art is that the user who is usually confronted with a large number of different samples has little support in automating his processes. In the system of the prior art shown in FIG. 1 individual vessels are used to process the sample so that when several samples are processed in parallel individual vessels are always present which can easily be mixed up. In contrast labelling each vessel means some work for the operator so that it is often not done. Mixing up samples can have disastrous consequences especially when processing nucleic acids which is frequently used to detect diseases or for criminal investigations.
There is still no known concept in the prior art which would suitably assist a user with a large number of samples either by accelerating the manual processing or automating the processing.
Hence an object of the present invention was to propose a system for providing biological materials which enables a coordinated, simple processing of a plurality of sample materials which prevents mistakes and contamination. A further object of the present invention was to provide a system and process which can adequately exclude the possibility of mistaking samples. A further aspect of the present invention relates to the problem of providing a closure design which takes into account the specific requirements needed to provide biological materials.
The above objects are achieved by a process for isolating a purified biological material comprising the following steps:
a) Placing biological materials in separate lysis vessels of a lysis unit comprising two or several lysis vessels in a predetermined geometric arrangement,
b) adding lysis liquids to the biological materials in the lysis vessels,
c) transferring the liquids in the lysis vessels into a matrix unit containing matrix vessels with outlet openings whose number corresponds to the number of lysis vessels which are arranged in a predetermined geometric arrangement and a matrix is located in each of the matrix vessels to which the biological material to be purified binds,
d) extracting the liquids in the matrix vessels through the outlet openings during which the liquids flow through the matrices,
e) placing the matrix unit on a collecting unit with collecting vessels which are arranged such that at least the outlet openings of the matrix vessels extend into the collecting vessels,
f) filling the matrix vessels with elution fluid,
g) extracting the elution fluids from the matrix vessels through their outlet openings during which the elution fluids flow through the matrices and the elution fluids which are enriched with biological material are collected in the collecting vessels.
The process mentioned above for obtaining purified biological materials has the advantage over the prior art that it enables the processing steps to be systematized due to the predetermined geometric arrangements of the lysis unit, matrix unit and collecting unit. The predetermined geometric arrangement of the lysis vessels which preferably corresponds to the geometric arrangement of the matrix vessels in the matrix unit makes it easier for the user to transfer a lysed biological material from a collecting vessel into the corresponding matrix vessel. Furthermore the arrangement of matrix vessels corresponds to that of the collecting vessels in such a manner that at least the outlet openings of the matrix vessels extend into the collecting vessels when the matrix unit is placed on the collecting unit.
The assembly of lysis vessels, matrix vessels and collecting vessels which forms the corresponding units has the additional advantage that it is not necessary to handle individual vessels but rather whole units can be moved whose size and shape are much easier to handle.
In the said process it is additionally possible to use codes on the individual units which enable a sample placed in a lysis vessel to be unambiguously assigned to the eluate that is finally collected.